=begin
File: stack.rb
Created Time: 2024-04-06
Author: Xuan Khoa Tu Nguyen (ngxktuzkai2000@gmail.com)
=end

### Driver Code ###

# 初始化栈
# Ruby 没有内置的栈类，可以把 Array 当作栈来使用
stack = []

# 元素入栈
stack << 1
stack << 3
stack << 2
stack << 5
stack << 4
puts "栈 stack = #{stack}"

# 访问栈顶元素
peek = stack.last
puts "栈顶元素 peek = #{peek}"

# 元素出栈
pop = stack.pop
puts "出栈元素 pop = #{pop}"
puts "出栈后 stack = #{stack}"

# 获取栈的长度
size = stack.length
puts "栈的长度 size = #{size}"

# 判断是否为空
is_empty = stack.empty?
puts "栈是否为空 = #{is_empty}"
